1,231 research outputs found
Production of Strange Clusters and Strange Matter in Nucleus-Nucleus Collisions at the AGS
Production probabilities for strange clusters and strange matter in Au+Au
collisions at AGS energy are obtained in the thermal fireball model. The only
parameters of the model, the baryon chemical potential and temperature, were
determined from a description of the rather complete set of hadron yields from
Si+nucleus collisions at the AGS. For the production of light nuclear fragments
and strange clusters the results are similar to recent coalescence model
calculations. Strange matter production with baryon number larger than 10 is
predicted to be much smaller than any current experimental sensitivities.Comment: 9 Pages (no figures
Charmonium Suppression by Comover Scattering in Pb+Pb Collisions
The first reports of and production from experiment NA50 at
the CERN SPS are compared to predictions based on a hadronic model of
charmonium suppression. Data on centrality dependence and total cross sections
are in good accord with these predictions.Comment: 9 pages, latex, 6 figures, epsf, figure added and text modified to
clarify result
LâIndice de biodiversitĂ© potentielle (IBP) en rĂ©gion mĂ©diterranĂ©enne
LâIBP est un outil pour Ă©valuer la biodiversitĂ© taxonomique ordinaire des peuplements forestiers. Rapide et simple Ă utiliser, il est basĂ© sur lâestimation indirecte de la biodiversitĂ© au travers de lâĂ©valuation de la capacitĂ© dâaccueil en espĂšces et en communautĂ©s, Ă lâĂ©chelle du peuplement forestier. Il consiste Ă apprĂ©cier un ensemble de dix facteurs parmi ceux qui sont habituellement reconnus comme les plus favorables Ă la diversitĂ© interne des peuplements. Un score de 0, 2 ou 5 est donnĂ© sur le terrain Ă chacun des facteurs selon une Ă©chelle de valeurs seuils et leur somme donne lâIBP. LâIBP est adaptĂ© Ă toutes les forĂȘts des domaines atlantique et continental. Lâextension Ă la rĂ©gion mĂ©diterranĂ©enne est Ă lâĂ©tude depuis 2009. Le domaine dâutilisation de lâIBP « mĂ©diterranĂ©e » a Ă©tĂ© prĂ©cisĂ©, tant au niveau gĂ©ographique quâau niveau des formations vĂ©gĂ©tales concernĂ©es. Les facteurs et les seuils ont Ă©tĂ© revus pour tenir compte des caractĂ©ristiques des forĂȘts mĂ©diterranĂ©ennes. La problĂ©matique des incendies est Ă©galement Ă©tudiĂ©e Ă travers les relations entre la biodiversitĂ© taxonomique et les feux de forĂȘt, car la forĂȘt mĂ©diterranĂ©enne est particuliĂšrement concernĂ©e
What information can we obtain from the yield ratio in heavy-ion collisions ?
The recently reported data on the yield ratio in central
rapidity region of heavy-ion collisions are analyzed by theoretical formula
which accounts for Coulomb interaction between central charged fragment (CCF)
consisting of nearly stopped nucleons with effective charge
Z_{\mbox{\scriptsize eff}} and charged pions produced in the same region of
the phase space. The Coulomb wave function method is used instead of the usual
Gamow factor in order to account for the finite production range of pions,
. For Gaussian shape of the pion production sources it results in a
quasi-scaling in and Z_{\mbox{\scriptsize eff}} which makes
determination of parameters and Z_{\mbox{\scriptsize eff}} from the
existing experimental data difficult. Only sufficiently accurate data taken in
the extreme small - region, where this
quasi-scaling is broken, could be used for this purpose.Comment: 7 pages, Latex type, 8 figure
A Psychometric Study of a Trait and State Assessment of Sexual Pleasure - The Amsterdam Sexual Pleasure Inventory.
We studied the Amsterdam Sexual Pleasure Inventory's (1.0) psychometric properties. The ASPI, a revised self-report battery designed to measure domains of state and trait sexual pleasure in diverse gender, sex, and relationship populations, is based on a recently proposed conceptual framework of sexual pleasure. We collected quantitative (nâ=â1371) and qualitative data (nâ=â637) using a cross-sectional multi-method design targeting the general (German-speaking) population. After pre-processing, we conducted analyses on a sample of nâ=â706 participants. The theory-based 5-factor exploratory structural equation model and the principal component analyses of the two general exploratory index-scales showed good and acceptable structural validity evidence respectively. Measurement invariance was confirmed separately for male and female participants and for those with sexually functional-scoring and dysfunctional-scoring levels. Coefficient omega indicated that all scales, except those of one facet, showed acceptable to very good internal consistency. The ASPI's convergent and discriminant associations with sexological and psychological constructs demonstrated good overall construct validity. Participants understood the items as intended and felt that the ASPI covered relevant facets of sexual pleasure. The ASPI might help understand how individuals differ in experiencing sexual pleasure and how different contexts enable some people to experience pleasure while disadvantaging others
Open Charm Enhancement in Pb+Pb Collisions at SPS
The statistical coalescence model for the production of open and hidden charm
is considered within the canonical ensemble formulation. The data for the
J/\psi multiplicity in Pb+Pb collisions at 158 A GeV are used for the model
prediction of the open charm yield. We find a strong enhancement of the open
charm production, by a factor of about 2--4, over the standard hard-collision
model extrapolation from nucleon-nucleon to nucleus-nucleus collisions. A
possible mechanism of the open charm enhancement in A+A collisions at the SPS
energies is proposed.Comment: 4 pages, Late
Testing of the 2.6 GHz SRF Cavity Tuner for the Dark Photon Experiment at 2 K
At FNAL two single cell 2.6 GHz SRF cavities are being used to search for
dark photons, the experiment can be conducted at 2 K or in a dilution
refrigerator. Precise frequency tuning is required for these two cavities so
they can be matched in frequency. A cooling capacity constraint on the dilution
refrigerator only allows piezo actuators to be part of the design of the 2.6
GHz cavity tuner. The tuner is equipped with three encapsulated piezos that
deliver long and short-range frequency tuning. Modifications were implemented
on the first tuner design due to the low forces on the piezos caused by the
cavity. Three brass rods with Belleville washers were added to the design to
increase the overall force on the piezos. The testing results at 2 K are
presented with the original design tuner and with the modification.Comment: 21st International Conference on Radio-Frequency Superconductivity
(SRF 2023
Charmonium suppression in p-A collisions
The new high precision data on charmonium production in proton-nucleus
collisions by the E866/NuSea collaboration at Fermilab allow - together with
older data at lower energies - to fix a unique set of parameters for the
standard production and absorption scenario of charmonium in a proton-nucleus
reaction. In this scenario the c-cbar pair is formed in an octet state, emits a
gluon and continues its radial expansion in a singlet state until it has
reached the charmonium radius. In all three phases it can interact with the
nuclear environment. We find that the lifetime of the octet state is much
shorter than acceptable on physical grounds. This challenges the physical
reality of the first phase in the standard scenario.Comment: 8 pages, 10 figure
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